In the past decade, several workers have applied a combinatorial synthesis approach to development of new materials, or to construction of known materials in new ways. Material chip samples, with varying chemical compositions involving two or three components and with discrete or continuous composition change, can, in principle, be synthesized, using multilayers and masks. However, a true multi-composition compound probably cannot be formed unless each multilayer is formed and uniformly diffused at relatively low temperatures. This appears to require an in situ approach, which is not well understood and is not developed in the background art.
What is needed is an in situ approach and/or a multilayer approach for formation of chemical compounds having two, three or more components and having controllably variable composition on a substrate. Preferably, the approach should be flexible and should easily allow change of one or more geometric, physical and chemical parameters describing the formation process and the variation of composition with location on the substrate. Preferably, the approach should allow a choice of the geometric variation (linear, nonlinear, etc.) of one or more composition parameters according to the intended use and environment of the material chip.